MINOR: Split at first occurrence of '=' in kafka.py props parsing (#5549)
MINOR: Split at first occurrence of '=' in kafka.py props parsing (#5549)

This is a fix to #5226 to account for config properties that have an
equal char in the value.   Otherwise if there is one
equal char in the value the following error occurs:

dictionary update sequence element #XX has length 3; 2 is required

Reviewers: Colin Patrick McCabe <342564bc1ab1e55103f85104b5e013adfdf828cb@cmccabe.xyz>, Ismael Juma <ismael@juma.me.uk>
lindong28/kafka,lindong28/kafka,gf53520/kafka,sslavic/kafka,Esquive/kafka,Esquive/kafka,noslowerdna/kafka,guozhangwang/kafka,sslavic/kafka,lindong28/kafka,mihbor/kafka,apache/kafka,gf53520/kafka,lindong28/kafka,mihbor/kafka,KevinLiLu/kafka,guozhangwang/kafka,noslowerdna/kafka,apache/kafka,mihbor/kafka,Chasego/kafka,sslavic/kafka,KevinLiLu/kafka,Chasego/kafka,Chasego/kafka,TiVo/kafka,TiVo/kafka,Esquive/kafka,gf53520/kafka,noslowerdna/kafka,apache/kafka,KevinLiLu/kafka,noslowerdna/kafka,TiVo/kafka,TiVo/kafka,mihbor/kafka,sslavic/kafka,apache/kafka,KevinLiLu/kafka,guozhangwang/kafka,Chasego/kafka,gf53520/kafka,guozhangwang/kafka,Esquive/kafka